"The most usual weather in these latitudes is a fresh wind between north west and south west with a cloudy overcast sky" - Phillip Parker King, Sailing Directions for the Coasts of Eastern and Western Patagonia (1832).

Patagonia is a beautiful place to visit but campers know that the weather is extremely variable and the sky is often cloudy. This can be a problem for glaciologists, too, since they rely on optical satellite imagery to study glacier area changes over the last decades (mainly Landsat). Clear-sky optical images can also be used to determine glacier velocity, albedo, front variations, etc.Continue reading

Kilauea Volcano in the largest active volcano in Hawaii and one of the most active on Earth. It has been erupting for over 30 years now but hit the headlines recently because a large lava flow traveled up to the ocean, adding 2 brand new hectares to the Hawaiian Islands.

Aerial view of the 61G lava flow ocean entry on August 19, 2016. Credit: U.S. Geological Survey Department of the Interior/USGS U.S. Geological Survey.

After reading my previous post about the Rutog ice avalanche, my distinguished colleagues Antoine R. and Olivier H. challenged me to look for a pre-event image to better highlight the avalanche area. The closest clear-sky image that I could find is a Landsat-8 image that was acquired on June 24 (23 days before the slide).

Sequence of two Landsat-8 and Sentinel-2A images. Both images are level 1 product displayed as natural color composites. Click to enlarge.

The Nature News website reported yesterday on a massive ice avalanche that happened in Rutog, Tibet, on 17 July 2016. This ice avalanche killed 9 people and may be one the largest ever observed. The ice and rock mixture spread over 6 km from the collapse point up to the Aru Co lake shoreline.

Sentinel-2A image of the Rutog ice avalanche acquired on 21-Jul-2016 (4 days after the event). Click on the image to see at full resolution (1 pixel = 10m).

NASA's blog "Image of the Day" recently featured two beautiful MODIS images of the snow cover in Lesotho. In late July Lesotho experienced its heaviest snowfall in two decades. The snow is not uncommon in Lesotho given that over 80% of the country lies above 1800 m (wikipedia). However the frequency of such snow events has been reducing over the past decades due to the ongoing climate change. As a result the shepherds are less accustomed to the snow conditions so that "a severe storm like the one in July 2016 has greater potential to kill sheep and shepherds" [1]. Continue reading

Dave Petley wrote a nice article in the AGU's Landslide blog about a massive landslide in Glacier Bay, Alaska. This huge avalanche of debris was spotted by a local pilot Paul Swanstrom on June 28. When Paul was above it, "dust was still flying". Later, based on earthquake records in Alaska, the experts figured out that it probably happened at 8:21 am on the same day.

Photo of the the Glacier Bay landslide in Alaska by Paul Swanstrom - MountainFlyingService (click on the image to see the Facebook photo album)

"well, after all you are probably right, but don't worry, we only use it to do quick and dirty stuff, not real scientific work"

As most (...) of these colleagues are quite sensible, I am not worrying too much. But as far as I am concerned, I would have some chances to be a victim of Mrs-Armitage-on-wheels Syndrom (AWS). I guess I do not need to explain it to our british colleagues who consult this blog, this syndrom originates form the great children book from Quentin Blake, that I used to read to my children, some time ago (every night for the two first weeks, then once in a while...) : Mrs Armitage on wheels. Another daddy reads it for you here.

Exceptional rainfall in May caused heavy flooding in the Paris region. Newspapers and TVs reported that the Seine flood forced the Louvre staff to move away from rising waters the art pieces that were stored in their cellar. But they did not tell you that about 50 km east of the Louvre museum, the flood of the Grand Morin river in Coulommiers also inundated the cellar of my parents-in-law. I'm really concerned about this cellar because I care about my parents-in-law of course, and also because I have let some of my bottles of wine in their cellar. Continue reading